Conventional rubber-modified styrene resin compositions have a low impact resistance as compared with an ABS resin, and therefore in order to elevate the impact resistance, rubber-like polymer grains having a grain diameter (rubber grain diameter) usually controlled to 1 to 3 .mu.m are dispersed in a styrene resin phase. However, there has been a problem that the inferior appearance thereof makes it difficult to use them for uses requiring an excellent appearance. Accordingly, proposed are a method in which for the purpose of improving a balance between the impact resistance and the gloss, a rubber-modified styrene resin composition having a rubber grain diameter of 1 .mu.m or less is blended a with silicone oil to make up the impact resistance (Japanese Patent Publication No. Hei 3-76338, Japanese Patent Publication No. Hei 5-11143 and Japanese Patent Publication No. Hei 5-45624) and a method in which in addition to the above, a proportion of a gel component to a rubber component is controlled (Japanese Patent Publication No. Hei 7-53816). However, a balance between the impact resistance and the rigidity has not yet been good in these methods. Further, it is proposed in Japanese Patent Publication No. Hei 3-62723 and Japanese Patent Publication No. Hei 1-34453 to improve the coloring property and the appearance by controlling the average grain diameter of an aromatic vinyl polymer included in a rubber-like material. In addition to this, proposed, for example, in Japanese Patent Publication No. Hei 5-25897 and Japanese Patent Publication No. Hei 5-18348 is a method in which rubber grains having a single occlusion (core shell, capsule) structure are blended with rubber grains having a salami structure to form a two-peak rubber grain diameter distribution, whereby a balance between the impact resistance and the gloss is improved to bring the characteristics close to those of an ABS resin. Any of these methods, however, causes such a problem that while high values are shown in measuring the gloss, the gloss intensity (visibility of the reflected image) observed when the actual molded articles are evaluated by eyes is insufficient and the reflected image on the surface of the molded article has a haze, and further that the molded articles have a low surface hardness and are lacking in an abrasion resistance, whereby they are limited in uses.
Thus, the balance of the gloss with the impact resistance and the rigidity is insufficient, and the satisfying quality has not yet been obtained. Accordingly, materials having an excellent balance therebetween has been expected to be developed.